摘要 |
<p>The invention provides an interpenetrating network polymer suitable for manufacturing contact lenses. The polymer comprises (a) a hydrophilic vinyl pyrrolidone, 50-80%; (b) (5-alkylene-m-dioxanyl) acrylic ester, 10-45%, having the formula wherein R and R1 are independently H or C1-C4 alkyl, R2 and R3 are independently H, C1-C4 alkyl, or phenyl, n is an integer from 1-4; (c) a first crosslinking agent having an affinity for hydrophilic vinyl amide, 0.1-1.0%, said first crosslinking agent being 3,3'-ethylidine-bis (N-vinyl-2-pyrrolidone), diallyl itaconate, diallyl maleate, diallyl fumarate, dimethallyl fumarate, dimethallyl maleate, diallyl diglycollate, diethylene glycol bis (allyl carbonate), diallyl oxalate, diallyl adipate, diallyl succinate, diallyl azelate, divinyl benzene, divinyl adipate, or divinylethers; and (d) a second crosslinking agent having an affinity for acrylic esters, 0.1-2.0%, said agent being neopentyl glycol dimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimetharcrylate, tetraethylene glycol dimethacylate, polyethylene glycol dimethacrylate, 1,6-hexane diol dimethacrylate, glycerol trimethyacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, trimethylol propane trimethylacrylate, allylmethacrylate, or corresponding acrylates; wherein the percentages are by weight based on the total weight of monomer exclusive of cross-linking agents.</p> |